5-[2-[7-(Trifluoromethyl)-5-[4-(trifluoromethyl)phenyl]pyrazolo[1,5-a]pyrimidin-3-yl]ethynyl]-2-pyridinamine (compound A) is a mGluR2 (metabotropic glutamate receptor) antagonist, which is useful for the treatment of depression and other CNS disorders. WO 2006/099972 describes a synthesis of compound A and its potential applications in treating central nervous system (CNS) disorders. Also disclosed in WO 2006/099972 are analogues and synthetic methods for making these analogues. These methods are unsuitable for the large scale manufacture of compound A required to support clinical programs and commercialization.